Hi
I don't understand why i have to "reproject " a radius expressed in NM, km... to obtain a good geometry and how to do it.
I always obtain a very big line ( radius = 23 NM for example) and a very little arc when i zoomed on the center of the line.
Is it possible to explain me the "reprojector" .
It's hard in english. .. :-(
it works on ground units . Which is determined by your coordinate systems.
if your units are meters and you want nautical miles you must convert the units. 1 nm =
1,852 meters. so circle with 23nm in a metric system, you need to enter 1/2*23*1852 m.
are you entering 23 for the radius?
i think you are creating a line 23nm and a arc of 23m, sounds like.
Hi
I have to build an arcbycenter geometry defined with the center point ( geolat and geolong in decimal degree coordinates - well done with a vertex creator ), a startAngle, an endAngle and a radius ( defined in various units - km, NM. ..) and output this geometry in gml format.
I obtained the good structure in Gml with all the elements ( poslist, StartAngle, sweepangle ) but the radius ( 23 NM in my example has to be translate in a value " ground unit " equal to 0,55).
I don't succeed to obtain this good value by a calculation. I obtained a very big line and when i zoom on the center of this line i see the arc.
it works on ground units . Which is determined by your coordinate systems.
if your units are meters and you want nautical miles you must convert the units. 1 nm =
1,852 meters. so circle with 23nm in a metric system, you need to enter 1/2*23*1852 m.
are you entering 23 for the radius?
i think you are creating a line 23nm and a arc of 23m, sounds like.
https://knowledge.safe.com/articles/725/calculating-accurate-length-in-meters-for-lat-long.html